Detection of Small Amounts of Chloral. 113 



pose of differentiating chloral from chloroform and only one reac- 

 tion in which formalin will not interfere. 



The first reaction: phloroglucin and sodium carbonate with 

 chloral, standing at room temperature for about one half hour grad- 

 ually develops lilac to orange, to blood orange, to deep red. If 

 extremely small quantities of chloral are present, the color de- 

 velops to orange only, and if as low as .01 mg. in one c.c. is present, 

 the color is a cross between orange and the light violet of the re- 

 agents themselves. Even in this extremely dilute solution a posi- 

 tive reaction may easily be recognized if compared with the con- 

 trol. Chloroform does not give this reaction. The color obtained 

 with chloroform on the other hand is the slight violet of the re- 

 agents themselves. Formaldehyde and acetaldehyde interfere in 

 that they give a reddish color. If the absence of aldehyde is 

 shown by the reduced fuchsin test (which is not given by chloral), 

 then the phloroglucin test may be looked upon as a sensitive 

 method for purposes of differentiation. The technique is as fol- 

 lows: 



To one c.c. of distillate add four drops of saturated phloro- 

 glucin and one c.c. of 20 per cent, sodium carbonate and allow to 

 stand. Gradually the color develops, lilac to orange, to blood- 

 orange, to deep red (sensitiveness, 0.01 mg. in one c.c). 



The reagents for the second method of differentiation are re- 

 sorcin and sodium carbonate. Resorcin with sodium hydroxide 

 and boiling have been used for a long time. Some workers, not- 

 ably Schwartz, 1 the originator of the test, claim that besides the 

 red color there is a green fluorescence given by both; others, 

 notably Witthaus, 2 claim that only chloral gives the fluorescence. 

 With the use of resorcin and sodium carbonate and at room tem- 

 perature for one half hour I find, first, that with chloroform a greeh 

 fluorescence never appears and that with chloral, even in minute 

 amounts, fluorescence always occurs; second, that although the red 

 color does not appear in very dilute solutions of chloral, the green 

 fluorescence, especially if the reaction product is diluted with 10 

 c.c. of water, is always present; third, its sensitiveness is .01 mg. 

 in one c.c; fourth, formadehyde, acetaldehyde, formic acid, ben- 



1 Zlschr.f. Anal. Chem., 1888, 27, 668. 



2 "Text-book of Medical Jurisprudence and Toxicology," Vol. 4, p. 1171. 



